Antenna lead-out insulator



y 17, 1932- c. B. MIRICK I 1,858,336

ANTENNA LEAD- QUT INSULATOR Filed Jan. 9, 1930 4 Sheets-Sheet l Eta-J- 55 Zia-i IN VEN TOR.

May 17, 1932. c. B MIRICK ANTENNA LEAD-OUT INSULATOR Filed Jan. 9, 1930 4 Sheets-Sheet 2 INVENTOR. v ada/a 5Y3. QW/IM,

q QQ

ERNEY lllllllllllmz May 17, 1932. g, M|R|K Q 1,858,336

ANTENNA LEAD-OUT INSULATOR Filed Jan. 9. 1950 4 Sheets-Sheet 5 A TTORNEY May 17, 1932. c. B. MlRlCK ANTENNA LEAD-OUT INSULATOR Filed Jah. 9. 1930 4 Sheets-Sheet 4 llllllllllH INVENTOR. M4 69.). 91mm BY Q ATTORNEY Patented May 17, 1932 UNITED. STATES PATENT ome CARLOS B. IIBICK,

ELECTRICAL SUPPLY POBATION OI VIRGINIA.

AN'LENNA LEAD-OUT INSUIIA'IOIB.

Application filed January 9, 1930. Serial No. 418,595.

My invention relates broadly to radio communication systems for aircraft and more particularly to'the construction of an antenna lead out insulator for use in aircraft radio installations.

One of the objects of my invention is to provide a construction of antenna lead out insulator which may be readily installed upon aircraft in a position which enables the weight or fish which connects to the end of the trailing wire antenna to be readily passed through the lead out insulator in the process of extending the antenna or reeling in the antenna at the end of a flight.

Another object of my invention is to provide a construction of lead out insulator .which may be installed aboard aircraft with means for normally closing the lead out insulator when the trailing wire antenna is not in use, the lead out fitting being readily opened to permit the reeling out of the trailing wire antenna when the radio communication system is to be placed in use during flight of the aircraft.

Still another object of my invention is to provide a construction of lead out insulator for installation aboard aircraft wherein a tubular member extends from a position adjacent the exterior of the aircraft to a position adjacent the antenna reel within the aircraft, the tubular member being enga eable by a plug for closing the tube or by a fltting through which the trailing wire antenna may be insulatingly extended from the antenna reel within the aircraft to a position trailing beneath the aircraft.

A further object of my invention is to provide a construction of lead out insulator attachable to the frame or hull of an aircraft for detachably receiving a plug or an insulating guide for an antenna wire for permitting the reeling out of an antenna from the aircraft during the operation ofthe communica tion system.

7 Other and further objects of my invention reside in the construction and arrangement of parts of the antenna lead out insulator described more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 is a fragmentary cross-sectional view through a portion of the hull of a flying boat showing the attachment of the antenna lead out insulator of my invention to the bull in a position adjacent the antenna reel, with a plug closing the end of the antenna lead out insulator within the aircraft; Fig. 2 is a schematic view showing the antenna lead out insulator partially broken away and in section, and showing the trailing wire antenna about to be projected through the insulator with the fish or weight still housed within the antenna lead out insulator; Fig. 3 is a view of the antenna lead out insulator with the trailing wire antenna extended therefrom preparatory to a reeling out or a reeling in operation; Fig. 4 illustrates the arrangement of the trailing wire antenna in its position of normal use; Fig.5 is a cross-sectional view taken through the antenna lead out insulator with parts thereof shown in side elevation; Fig. 6 is a top plan view of the antenna lead out insulator; Fig. 7 is a cross-sectional view taken through the antenna lead out insulator of Fig. 5 on line 77 thereof; Fig. 8 is a crosssectional view taken through the antenna lead. out insulator on line 8-8 of Fig. 5; Fig. 9 is a cross-sectional view taken through the antenna lead out insulator on line 99 of Fig. 5; Fig. 10 is a cross-sectional view taken through the antenna lead out insulator on line 1010 of Fig. 5; Fig. 11 is a crosssectional view taken through the externally projecting portion of the antenna lead out insulator on line 11'-11 of Fig. 5; Fig. 12 is a fragmentary vertical cross-sectional view through the antenna lead out insulator on line 1212 of Fig. 5; Fig. 13 shows the antenna lead out insulator about to be telescopically fitted into the inwardly projecting tube of the antenna lead out insulator; Fig. 14 is a perspective view illustrating the cam members under which the insertable insulator or plug is secured adjacent the interior end of the antenna lead out insulator; Fig. 15 is a vertical sectional view through the antenna lead out insulator shown= partially in side elevation and illustrating the plug in position for closing the inner end of the tubular member forming part of the antenna lead out insulator; and Fig. 16 shows the plu in the process of insertionor withdrawal rom the tubular member forming a part of the an tenna lead out insulator.

In installations of radio communication apparatus aboard aircraft, it has been usual to employ a trailing wire antenna in the transmission of signals from the aircraft. Reception may be carried on by the use of loops or short conductors in the nature of skid fin antennae erected upon the aircraft, or wires extending along the planes of the aircraft. However, for transmission purposes it has been found important to employ a trailing wire antenna. Various forms of insulators have been proposed for passing the wire through the hull of the aircraft, but prior forms of insulators have proven defective by reason of mechanical or electrical break down or by reason of the obstruction offered by the fish or weight to the passage of the trailing wire from a position interiorly 0f the aircraft to a position exteriorly there of. That is to say in prior forms of lead out insulators for aircraft the trailing wire with Weight attached has necessarily extended outside of the aircraft in a position substantially hanging adjacent the exterior wall of the aircraft preparatory to a projecting operation. In my construction of antenna lead out insulator, I provide a tubular fitting which extends from a position adjacent the exterior of the aircraft to a position interiorly thereof, adjacent the antenna reel. The tubular tting is provided with cam shaped members adjacent the interior end thereof under which the antenna lead out insulator may be engaged and locked in position, or with respect to which a dummy plug may be inserted and securedin position. The tubular member is of such size that the trailing wire antenna with the weight or fish attached thereto may be projected through the tubular member or withdrawn from its projected position after the transmission is completed. I provide means for locking the'antenna lead out insulatorthrough a bayonet slot connection with the tubular member. The lead out insulator maintains .the antenna wire in insulated spacial relation to the interior walls of the tubular member. Hardened metal bushings are provided in eachend of the antenna lead out insulator for avoiding the wearing away of the ends of the insulator during the process of reeling out and reeling in of the trailing wire antenna.

The fish or weight which is connected to the end of the trading wire antenna may be of any suitable construction such as described in my copending application Serial No. 412,- 121, filed December 6, 1929.

The mass of the antenna weight or fish is such as to maintain the trailing wire in such position beneath the aircraft while in flight as to secure a maximum vertical component for signaling purposes. After the trailing wire is reeled in, the antenna lead out insulator is removed from the tubular member which extends from the hull of the aircraft and a dummy plug inserted in place thereof, serving to substantially seal the end of the tubular member and prevent the passage of water through the tubular member to the interior of the aircraft. The tubular member is always mounted so that the upper end thereof terminates substantially above the water line when the device is installed on a flying boat. The construction of the insulator is such that seepage of water into the aircraft is prevented, both by the construction of antenna lead out insulator and by reason of the construction of dummy plug. Water may tend to back up in the tubular member when an am I phibian plane is riding a heavy sea, or when the plane is taking off or landing but seepage of the water into the aircraft is prevented by the watertight seal provided by the joint between the antenna insulator and the tubular member or between the dummy plug and the tubular member.

- The antenna lead out insulator of my i11- vention has proven highly successful and practical in its construction and while for the purposes of illustrating my invention I will describe one preferred embodiment thereof, it is to be understood that modifications may be'made by those skilled in the art without departing from' the spirit or scope of my invention. v

In the drawings, I have shown my invention as applied to a flying boat but it will be .understood that my lnvention is equally applicable to land planes.

Referring to the drawings in more detail, reference character 1 indicates the hull of the aircraft or flying boat, floatin on the surface of the water 2, the aircraft eing equipped with the antenna leadout insulator of my invention. The antenna lead out insulator includes the tubular member 3 which is screw threaded into the bushin 4 provided with a fl ange suitably secured y rivet members 5 to the hull of the aircraft. A reel 6 carrying the antenna wire 7 is shown mounted in position above the antenna lead out insulator. In Fig. 1 the antenna lead out insulator is shown closed-by the plug 9 which has a portion 10 extending longitudinally through the tubular member 3. The portion 10 of the plug 9 has an enlarged body portion 11 thereon which substantially closes the portion of the tubular'member 3 which is immediately adjacent the hull 1, andchecks the inrush of water when the craft is riding a heavy sea or ing the fish 8 connected thereto is passed through the tubular portion 3 preparatory to the projection thereof from the aircraft. The

. antenna lead out insulator per se, .is shown at 14 partially projected into the interior of the tubular member 3, thebushing 15 of insulator 14 substantially conforming in shape to the interior cross-section of the tubular member 3. The fish or weight 8 is shown housed within the tubular member 3 preparatory to the reeling out of the antenna 7. In order to maintain control of the antenna wire 7 loops may be taken around the laterally extending portion 12 of the lead out insulator as represented at 7a.

' In Fig. 3 I. have illustrated the succeeding step in the reeling out of the antenna wire where the lead out insulator is locked in position with respect tothe tubular member 3 and the fish or weight 8 is dropped down free of the aircraft preparatory to the reeling out operation. i

In Fig. 4, the trailing wire antenna 7 is shown reeled out from the antenna reel 6 in a substantially vertical position during flight under control of the weight or fish 8.

In Fig. 5, I have shown in more detail the structure of the antenna lead out insulator wherein the laterally extending member 12 is secured by means of screws 12a to the insu'- latedhead 16 which is provided with radially projecting studs -17Zset in position by means of screws 12a. The head 16 is secured to the tubular insulator 14 by means of pins 18 shown more clearly in Figs. 9 and 12. The tubular member 3 .is screw threaded at eachend thereof, one end engaging the internal screw'threads of the flanged bushing 4 and the other end carrying the cylindrical member 19. An inwardly extending integral flange 20 is provided-in the cylindrical'memmember 26 in an annular recess formed in the ber 19 against which the head 16 is secured. The head 16 carries cylindrical plate 23 which is, centered with respect to the head 7 16 by lost motion connecting means consti .tuted by screw devices 24. A gasket 25 is secured in position against a metallic washer head 16. A pair of bayonet members 21 and 22 are secured internally within the cylindrical member 19 by means of screws 21a and 22a. The pro'ecting studs 17 are free topass between .t e separated ends of the bayonet shaped members 21 and 22 in the insertion or removal of the insulator from the tubular member 3 and by reason of the cam "shaped faces formed on the bayonet members,

a substantially watertight seal may be -established between the end of the tubular member 3 and the insulator which projects therein. The lower extremity of the tubular insulator'14 is fitted with the metallic terminus 27.'secured in the tubular member '14 by means of set'screw 27a. The antenna her 14 which has at the upper end thereof the metallic bushing 40, which is screw threaded into the insulated tubular member 14. The antenna wire 7 passes through the small bore in the bushing 40 and a similar bore in the bushing 27 as the wire is reeled out and trailed beneath the aircraft in flight. The bushing 15 which is carried by'the tubular insulator 14 is pinned to the tubular insulator 14 by radially projecting pins 15a shown more clearly in Fig. 7. The size of the bushing 15 is such that the exterior end of the tubular member 3 is substantially closed against the inrush 'of air or water andthe pressure of the water within the interior of the tubular member 3 due to impact or wave motion, substantially. broken. When the antenna wire is to be extended, the fish or weight 8 is let down through the tubular member 3 which has an interior surface diameter sufficiently large to permit the weight orfish 8 to'pass through. The antenna wire 7 isv first threaded through the insulator 14 and then the weight 8 attached thereto. The

weight 8 is then let down through the tubular as shown in Fig. 5. When the antenna wire is to be reeled in, the wire in coiled upon reel ;6 until the fish abuts against the outer extremity of the bushing 27 at the end of the insulator 14 and then the entire assembly withdrawn from the tubular member 3 to a position within the aircraft. The weight or fish 8 may be then detached from the antenna wire 7 and the antenna wire entirely coiled upon the reel 6.

To avoid the inrush of water. when the flying boat is riding a heavy sea or taking off or landing, it is essential to plug the tubular member 3- and for this purpose I provide the plug shown more clearly in Figs. 15 and 16 having a laterally extending end clip 9 similar to the laterally extended portion of the antenna lead out insulator. Screws 9a pass through the head 29 and through the studs 28 which extend radially therefrom. A tubular member 10 is secured to the head 29 by laterally extendingpin- 34. The upper end of tubular member 10 is provided with plug 35 secured in position therein by means of pin 35a. The lower end of tube 10 is plugged as represented at 36. An annular bushing 11 similar to bushing 15 in Fig. 5 which substantial ly conforms to the interior diameter of the tube 3, is pinned to the tube by means of 'pin 11a and blocks or breaks the tendency of lead out insulator in Fig. 5. 'slhat is the lost motion plate 31 is secured in position with respect to the insulated head 29 by screw members 30 which serve to confLe the gassleeve 19 and the head 29 to substantially close the tubular member 3. A watertight seal is provided by moving the studs 28 to the limit of their movement under the cam shaped members 21 and 22 in a manner similar to the movement of studs 17 of the antenna lead out insulator of Fig. 5. The dummy plug is placed in position at times when the antenna lead out insulator is removed, and can be readily withdrawn for the substitution of the antenna lead out insulator whenever it is required.

In radio installations upon aircraft, it very often occurs that the lead weight or fish is broken away from the end of the antenna wire. In the antenna lead out insulator of my invention it is only necessary to reelin the remainder of the. trailing wire antenna, withdrawthe insulator member from the housing, and renew the lead weight or fish by the attachment thereof to the free end of the trailing wire antenna, thread the wire with weight attached throu 'h the tubular member and restore the insul tor in the head thereof.

While Ihave described my invention in one of its preferred embodiments, I desire that it be understood that modifications can be made. and no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. An antenna lead out insulator for 'aircraft comprising. a, metallic tubular. member attachable to thehull of an aircraft and ex- .crafty comprising a tubular member attachable-to the aircraft in a position adj acent. the exterior-thereof, an insulator. telescopically insertable through said tubular member from.

the interior of the aircraft and projectible beyond the limits of said tubular member. with the exterior walls of said insulator spaced from the interior walls of said tubular member, and means carried by said insulator for guiding an antenna wire therethrough to a position trailing from the aircraft.

3. An antenna lead out insulator comprising a tubular member attachable to the hull of an aircraft, a tubular insulator projectible through said tubular member, means on said tubular insulator for detachably engaging the interior end of said tubular member, insulation means carried by said tubular insulator for spacing said insulator from the interior walls of said tubular member, said tubular insulator being formed to guide a weighted antenna wire from a position within the aircraft to a position trailing below the aircraft. p

4. An antenna lead out insulator for aircraft, comprising a tubular member attachable to the hull of the aircraft, a tubular insulator insertable through said tubular membetween said insertable tubular insulator and said tubular member, and means adjacent the lower end thereof. for spacing said insulator from the interior walls of said tubular member, said insertable insulator having means for guiding an antenna wire from a position within the aircraft to a position trailing beneath the aircraft. Y

5. An antenna lead out insulator for aircraft comprising a metallic tubular member attachable to a position adjacent the frame of the aircraft, an insulator projectible through said tubular member, means for detachably locking said insulator adjacent the interior end of said tubular member and spacing said insulator from the interior walls of said metallic tubular member, said insulator having means for guiding an antenna wire therethrough from a position interior. of said aircraft to a position trailing beneath the aircraft.

6. An antenna lead out insulator for aircraft, comprising a tubular member attachable to the frame of the aircraft and extending interiorly thereof, a bayonet groove head on said tubulai member, an insulator projectible through. said tubular member and having a sleeve portion formed thereon and engageable with the bayonet groove'head on said tubular member for the insertion or detachment of said insulator from said tubular member, said insulator having means for guiding an antenna wire therethrough froma position Within the aircraft to a position trailing beneath the aircraft.

7. An antenna lead out insulator for aircraft comprising a tubular member attachable to 'the frame of the aircraft and extending to a position interiorly thereof, an 'insulator insertable through said tubular memher and projectible beyond each end thereof, I

said insulator having a sleeve formed thereon adjacent each end thereof, and means carried by said sleeve adjacent the interior end of said tubular member for engaging said tubular member and locking said insulator in spaced relation to the interior walls of said tubular member, said insulator having means for guiding an antenna wire therethrough from a position interiorly of the aircraft to a position trailing beneath the aircraft.

8. An antenna lead out insulator comprising a housing attachable to the frame of an aircraft for detachably receiving an antenna lead out insulator therethrough and a dummy plug insertable within said housing, means for detachably locking said dummy plug in a position within said housing for closing the passage of the antenna wire therethrough.

9. An antenna lead out insulator comprising a housing attachable to the frame of an aircraft, an insulator telescopically projectible through said housing, a hand grip connected with the interior end of said insulator, spacing means adjacent opposite ends of said insulator substantially conforming to the interior cross-section of said housing, means carried by one of said spacing means being for detachably'engaging the interior end of said housing, the other of said spacing means being arranged to substantially close the exterior end of said housing.

10. An antenna lead out insulator for aircraft comprising a frame attachable to an aircraft, an insulator telescopically projectible through said housing,'a sleeve carried by the interior end of said housing, a head carried by said insulator, a hand grip connected with said head, and meansprojecting from said head and engageable with parts secured to said sleeve for substantially maintaining said insulator in position within said housing with the exterior walls of said insulator spaced from the interior walls of said housing, and means carried by said insulator and aligned with the opposite end of said housing for substantially closing the entrance to the interior of said housing from the exterior of the frame of the aircraft.

11. An antenna lead out insulator comprising a metallic tube connected with the hull of an aircraft and extending to a pos1t1on within the aircraft, connecting means on the interior end'of said metallic tube, a tubular insulator proje'ctible through said metallic tube, complementary means adjacent one end of said tubular insulator for engaging the connecting means on said tube and a laterally extending member secured'to the in-. terior end of said tubular'ins'ulator and 12. An antenna lead out insulator for the antenna wire of an aircraft comprising a conduit connected to the hull of the aircraft and extending to a position interiorly thereof through which the weighted fish of a trailing wire antenna may be freely passed, a collar formed on the interior end of said conduit, a tubular insulator projectible through said conduit to a position beyond the hull of the aircraft, and means carried by said tubular insulator forestablishing an interlocking engagement with the interior end of said conduit, and laterally extending members projecting from the'collar on said tubular insulator and adapted to be engaged by the antenna wire for maintaining the antenna wire in predetermined position with respect to said lead out insulator.

13. An antenna lead out insulator for aircraft, comprising a conduit secured to the,

hull of the aircraft and projectible to a position within the aircraft, ahead formed on. the interior end of said conduit, a tubular insulator projectible through said conduit and having a'complementary head adjacent one end thereof adapted to removably engage the head on said conduit, the head on said tubular insulator having a pair of laterally extending arms providing a hand grip for removably sliding said tubular insulator longitudinally through said conduit to a position in which the head on said tubular insulator engages the head on said conduit, and means carried 1) said'tubular insulator for spacing said tubu ar insulator from the'interior walls of said conduit, said tubular insulator havill:

, adapted to provide a tie means'around which I the antenna wire may be wrapped, the antenna wire extending through said tubular insulator and'having a weight thereon adapted to be passed through said metallic tube. when interconnecting the complementary connecting ortions of said tubular insulator and sai metallic tube. a v 

